Question: Christopher has biked his bike for a total of $15$ kilometers since he started biking daily. He has been biking $5$ kilometers each day. For how many days has Christopher been biking?
Answer: The number of days that Christopher has been biking is the total number of kilometers biked divided by the number of kilometers biked each day. $15\text{ kilometers} \div 5\text{ kilometers per day} = \text{number of days biking}$ $15\text{ kilometers} \div 5\text{ kilometers per day} = 3\text{ days}$